Fusion System Research Articles

Mechanical Performance of Laser Powder Bed Fused Ti-6Al-4V: The Influence of Filter Condition and Part Location

Deteriorated filter condition in laser powder bed fusion (L-PBF) systems may negatively impact shield gas flow, causing inadequate spatter particle/plume removal, leading to laser beam attenuation and reduction in melt pool depth, and potentially causing more frequent formation of volumetric defects. This work investigated the effects of filter condition and part location on the micro-/defect-structure and mechanical behavior, including tensile and fatigue, of Ti-6Al-4V parts fabricated by L-PBF. Interestingly, within the manufacturer recommended service intervals, no specific effect of filter condition could be observed on the micro-/defect-structure or the mechanical behavior of the fabricated parts. However, the parts’ defect-structures were affected by their location, with ones located near the center of the build plate having less porosity than the ones located away. Although these defects did not affect the tensile properties, they frequently observed to initiate fatigue cracks; the critical defects sizes were often in the range of a few tens of micrometers. Therefore, their sensitivity to location resulted in the location dependence of the fatigue behavior.

Effect of buprenorphine delivered by target-controlled infusion on the minimum alveolar concentration of isoflurane in cats

ObjectiveTo characterize the effect of buprenorphine on the minimum alveolar concentration of isoflurane (MACiso) in cats. Study designRandomized, crossover experimental study. AnimalsA group of six healthy 2 to 8 years old male neutered cats, body mass 5.0 ± 0.3 kg. MethodsThe MACiso had been determined in each cat in a previous study. Cats were anesthetized with isoflurane in oxygen. Catheters were placed in a medial saphenous vein for drug and fluid administration and in a jugular vein for blood sampling. Buprenorphine was given intravenously using a target-controlled infusion system to reach and maintain plasma concentrations of 0.5, 1, 2, 4, 8, 16, 32 and 64 ng mL-1 and MACiso was determined in duplicate at each concentration using the tail clamp technique. Four target plasma buprenorphine concentrations were administered on each study day, with at least 2 weeks between experiments. Blood was sampled after the second MAC determination at each target for determination of plasma buprenorphine concentration. ResultsA significant effect of buprenorphine on MAC was found; however, pairwise comparisons to MACiso without buprenorphine did not reach statistical significance. Maximum reduction in MACiso in individual cats ranged from 2 to 34% at plasma buprenorphine concentrations ranging from 0.25 to 8.15 ng mL-1. Conclusions and clinical relevanceAlthough buprenorphine significantly affected MACiso in cats, the magnitude of the effect and the plasma concentration at which the largest effect occurred was highly variable among cats, limiting the clinical usefulness of buprenorphine as an agent to reduce MAC in cats.

Evaluating neonatal pain via fusing vision transformer and concept-cognitive computing

In clinical nursing, neonatal pain assessment is a challenging task for preventing and controlling the impact of pain on neonatal development. To reduce the adverse effects of repetitive painful treatments during hospitalization on newborns, we propose a novel method (namely pain concept-cognitive computing model, PainC3M) for evaluating facial pain in newborns. In the fusion system, we first improve the attention mechanism of vision transformer by revising the node encoding way, considering the spatial structure, edge and centrality of nodes, and then use its corresponding encoder as a feature extractor to comprehensively extract image features. Second, we introduce a concept-cognitive computing model as a classifier to evaluate the level of pain. Finally, we evaluate our PainC3M on various open pain data sets and a real clinical pain data stream, and the experimental results demonstrate that our PainC3M is very effective for dynamic classification and superior to other comparative models. It also provides a good approach for pain assessment of individuals with aphasia (or dementia).

Implementation of an indoor optical camera communication and localization fusion system using infrared LED markers

Recently, with the development of communication and positioning technologies, progressively higher demands have been placed on the timeliness of indoor communication and the effectiveness of indoor positioning. This paper proposes a low-cost and full-time domain coverage indoor communication and localization fusion system that uses an infrared camera to identify mobile LEDs based on region of interest optical camera communication (RoI-OCC) and calculate three-dimensional (3D) world coordinates based on perspective-n-point (PnP) algorithm. An intermediate delimiter modulation-demodulation method is designed to achieve asynchronous OCC. In processing infrared images, a region-growth-based absolute-directional-mean-difference (RG-ADMD) algorithm is developed to detect infrared targets and recover the scale. Additionally, a local-contrast-method-based Lucas-Kanade (LCM-LK) optical flow estimation algorithm is designed to track infrared targets and determine the centroid coordinates of pixels. In a 5×5 m experimental area, the established system can achieve a target detection recall rate of over 85%, the asynchronous OCC with error-free transmission and an average 3D positioning accuracy of 2.01 cm under a LCM-LK tracking algorithm.

Specialized contact sites regulate the fusion of chlamydial inclusion membranes

The intracellular bacterial pathogen Chlamydia trachomatis replicates within a membrane-bound compartment called the inclusion. Upon infection with several chlamydiae, each bacterium creates its own inclusion, resulting in multiple inclusions within each host cell. Ultimately, these inclusions fuse together in a process that requires the chlamydial protein IncA. Here, we show that inclusions form unique contact sites (inclusion contact sites, ICSs) prior to fusion, that serve as fusogenic platforms in which specific lipids and chlamydial proteins concentrate. Fusion depends on IncA clustering within ICSs and is regulated by PI(3,4)P2 and sphingolipids. As IncA concentrates within ICSs, its C-terminus likely interacts in trans with IncA on the apposing membrane, securing a high concentration of IncA at fusion sites. This regulatory mechanism contrasts with eukaryotic or viral fusion systems that are either composed of multiple proteins or use a change in pH to initiate membrane fusion. Thus, our study demonstrates that Chlamydia-mediated membrane fusion is primarily regulated by specific structural domains in IncA and its local organization on the inclusion membrane, which is affected by the host cell lipid composition.

Smart Factory Operation Management System and Innovation in the Era of Smart Manufacturing

This study is dedicated to the innovative research of smart factory operation management systems in the era of smart manufacturing. Against the backdrop of the rapid evolution of the information revolution, smart manufacturing, represented by a new generation of information technologies such as mobile Internet, big data, and artificial intelligence, is rapidly emerging. As an information-physical fusion system, smart factories interpenetrate physical and virtual resources by interweaving multi-scale production systems, forming an open, complex giant system with multiple levels and dimensions. It is found that smart factories face a complex and variable structure, and their production and operations involve a large number of cross-domain, cross-industry, and cross-region manufacturing resources, requiring the establishment of a new operation management system framework and breakthroughs in key theories and methods. This study provides comprehensive and in-depth theoretical and technical support for constructing a smart factory operation management system. It lays the foundation for the smart upgrading of the manufacturing industry.

Fire Recognition Method Based on PSO-BP Neural Network and ResNet50

The rapid development of modern society and continuous urbanization have resulted in a proliferation of functional buildings, which offer significant convenience to individuals, but pose significant fire hazards as well. How to detect the fire at the early stage is always the focus of research. This paper proposes a multi-information source fusion fire recognition method based on particle swarm optimization (PSO)-backpropagation (BP) neural networks and ResNet50. The PSO algorithm is applied to optimize the initial parameters of a BP neural network model, while data from three sensors — temperature, humidity and smoke — are integrated, through iterative training of the system, accurate recognition of sensor data can be achieved. Additionally, a method is proposed for the recognition of infrared fire images using ResNet50 and transfer learning. By improving the ResNet50 network model and migrating the ResNet50 pre-trained network weight, infrared fire image recognition accuracy is further enhanced. Then the sensor information recognition results and image information recognition results are input into the fuzzy system for fusion reasoning again, and the final decision is output according to the set fuzzy rules. Experimental findings demonstrate that the multi-information source fusion approach utilizing the PSO-BP neural network and ResNet50 significantly enhances the accuracy and response time of fire recognition, and achieves a remarkable recognition effect.

Resilience analysis of mine ventilation cyber-physical fusion system

Resilience analysis of mine ventilation cyber-physical fusion system

A novel anti-CTLA-4 nanobody-IL12 fusion protein in combination with a dendritic cell/tumour fusion cell vaccine enhances the antitumour activity of CD8+ T cells in solid tumours.

We previously developed a nanobody targeting CTLA-4 and demonstrated that it can boost antitumour T-cell responses in vitro; however, the resulting responses after the injection of T cells into cancer models are usually weak and transient. Here, we explored whether fusing our nanobody to IL-12 would enable it to induce stronger, longer-lasting T-cell immune responses after exposure to immature dendritic cell and tumour cell fusions. The fusion protein enhanced the response of CD8+ T cells to tumour antigens in vitro and led to stronger, more persistent immune responses after the T cells were injected into mice bearing different types of xenografts. Our in vitro and in vivo results suggest the anticancer potential of our nanobody-interleukin fusion system and support the clinical application of this fusion approach for various nanobodies.

Effect of intravenous versus inhaled anesthetics on blood-brain barrier dysfunction and neuroinflammation in elderly patients undergoing major surgery: study protocol of a randomized controlled trial

BackgroundPostoperative cognitive dysfunction (POCD) is one of the major complications after surgery, with devastating clinical outcomes. Although POCD is a condition with a multifactorial pathophysiology, blood-brain barrier (BBB) dysfunction and neuronal injury have been shown to play a critical role, especially in the elderly. Previous studies have demonstrated that the choice of anesthetics affect BBB permeability and neuroinflammation. However, most studies are carried out on animals, with limited research undertaken on humans. Therefore, we will compare the effect of intravenous anesthetics and inhaled anesthetics on BBB dysfunction and the change of inflammatory markers after surgery.MethodsOne hundred and fifty-four patients who are 60 years of age or older undergoing major surgery for more than 2 h will be randomly allocated to two anesthetics groups (intravenous, inhaled) in a 1:1 ratio. In the intravenous anesthetics group (group P), propofol will be infused with a target-controlled infusion (TCI) system throughout the entire surgery. In the inhaled anesthetics group (group G), bolus injection of propofol will be administered for loss of consciousness, and simultaneously sevoflurane will be initiated for the maintenance of anesthesia. The primary outcome is the change in serum S100 calcium binding protein β (S100β) at four time points: before induction of anesthesia, at the end of surgery, 4 h after surgery, postoperative day 1. Secondary outcomes include changes in the inflammatory markers, serum interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, and C-reactive protein; the incidence of delirium; and the change in the cognitive function between groups. In patients pre-scheduled for postoperative intensive care unit admission, the cerebrospinal fluid/serum albumin quotient (Qalb) between the two groups will be compared before and after surgery, and change in inflammatory markers in serum and CSF will be analyzed in relation to the Qalb.DiscussionThe current study will compare the effect of intravenous versus inhaled anesthetics on blood-brain barrier permeability and, as a result, the difference in neuroinflammation in elderly patients. Also, the study results will provide additional information to develop intraoperative anesthetic strategies to reduce POCD.Trial registrationThe trial was prospectively registered at Clinical Trials protocol registration with identifier 2310-117-126 on April 9, 2024.

Attainment of high critical current in thick BaZrO3-doped YBa2Cu3O7 multilayer nanocomposite films

High critical current (Ic) in high magnetic fields (B) with minimal variations with respect to the orientation of the B field is demanded by many applications such as high-field magnets for fusion systems. Motivated by this, this work studies 6 vol. % BaZrO3/YBa2Cu3O7 (BZO/YBCO) multilayer nanocomposite films by stacking two 10 nm thick Ca0.3Y0.7Ba2Cu3O7 (CaY-123) spacers with three BZO/YBCO layers of thickness varied from 50 to 330 nm to make the total film thickness of 150–1000 nm. The Ca diffusion from the spacers into BZO/YBCO was shown to dramatically enhance pinning efficiency of c-axis aligned BZO nanorods, which yields high and almost thickness independent critical current density (Jc) in the BZO/YBCO multilayer nanocomposite films. Remarkably, enhanced Jc was observed in these multilayer samples at a wide temperature range of 20–80 K and magnetic fields up to 9.0 T. In particular, the thicker BZO/YBCO multilayer films outperform their thinner counterparts in both higher value and less anisotropy of Jc at lower temperatures and higher fields. At 20 K and 9.0 T, Ic is up to 654 A/cm-width at B//c in the 6% multilayer (1000 nm) sample, which is close to 753 A/cm-width at B//ab due to the intrinsic pinning. This result illustrates the critical role of the Ca cation diffusion into the YBCO lattice in achieving high and isotropic pinning in thick BZO/YBCO multilayer films.

Parametrical Choice of the Optimized Fusion System for a FFHR

Fusion–fission hybrid reactors are concepts of subcritical reactors based on the coupling of fusion and fission devices. In this case, the fusion reactor would work as an external neutron supplier for the fission core of the machine. Such systems could, in principle, operate as multi-purpose machines, such as energy generators, breeders and waste burners. The large availability of fusion and fission technologies makes the choice of devices to couple quite chaotic. In fact, most of the concepts proposed in the literature are based on attempts without real optimization. The purpose of this paper is to propose a parameter which could provide practical information regarding the choice or the design of the fusion system of an FFHR. An engineering approach based on the estimation of the energy efficiency of FFHRs was used. An evaluation of the parameter and some of its possible practical applications are shown. Obtained results indicate that, from a geometrical point of view, compact machines would need lower Q-values to reach high neutron source performance.

Optimization of DC Energy Storage in Tokamak Poloidal Coils

Tokamaks are a very promising option to exploit nuclear fusion as a programmable and safe energy source. A very critical issue for the practical use of tokamaks consists of the power flow required to initiate and sustain the fusion process, in particular in the poloidal field coils. This flow can be managed by introducing a DC energy storage based on supercapacitors. Because such storage may be the most expensive and largest part of the poloidal power supply system, an excessive size would cancel its potential advantages. This paper presents innovative strategies to optimize the DC storage in poloidal power supply systems. The proposed solution involves the sharing of the DC storage between different coil circuits. The study is supported by novel analytical formulas and by a circuital model developed for this application. The obtained results show that this method and the related algorithms can noticeably reduce the overall size of the storage and the power exchange with the grid, providing a practical contribution toward the feasibility and the effectiveness of nuclear fusion systems.

Development of a high current density, high temperature superconducting cable for pulsed magnets

Abstract A low AC loss Rare Earth Barium Copper Oxide (REBCO) cable, based on the VIPER cable technology has been developed by Commonwealth Fusion Systems for use in high field, REBCO based tokamaks. The new cable is composed of partitioned and transposed copper ‘petals’ shaped to fit together in a circular pattern with each petal containing a REBCO tape stack and insulated from each other to reduce AC losses. A stainless steel jacket adds mechanical robustness—also serving as a vessel for solder impregnation—while a tube runs through the middle for cooling purposes. Additionally, fiber optic sensors are placed under the tape stacks for quench detection. To qualify this design, a series of experiments were conducted as part of the SPARC tokamak Central Solenoid Model Coil program—to retire the risks associated with full scale, fast ramping, high flux HTS Central Solenoid (CS) and Poloidal Field (PF) coils for tokamak fusion power plants and net energy demonstrators. These risk study and risk reduction experiments include (1) AC loss measurement and model validation in the range of ~5 T/s, (2) an IxB electromagnetic loading of over 850 kN/m at the cable level and up to 300 kN/m at the stack level, (3) a transverse compression resilience of over 350 MPa, (4) manufacturability at tokamak relevant speeds and scales, (5) cable to cable joint performance, (6) fiber optic based quench detection speed, accuracy, and feasibility, and (7) overall winding pack integration and magnet assembly. The result is a cable technology, now referred to as PIT VIPER, with AC losses that measure fifteen times lower (at ~5 T/s) than its predecessor technology; a 2% or lower degradation of critical current (Ic) at high IxB electromagnetic loads; no detectable Ic degradation up to 570 MPa of transverse compression on the cable unit cell; end to end magnet manufacturing, consistently producing Ic values within 7% of the model prediction; cable to cable joint resistances at 20 K on the order of ~15 nΩ; and fast, functional quench detection capabilities that do not involve voltage taps. This cable technology will be tested comprehensively in a Central Solenoid Model Coil to prove its readiness for compact, high field tokamak operation.

Multi-Sensor fusion and semantic map-based particle filtering for robust indoor localization

To enhance positioning accuracy and ensure long-term stability in large-scale indoor environments, this paper presents a robust particle filtering method that integrates IMU, magnetic field, Bluetooth, and semantic map data, implemented through a handheld portable device. In the particle prediction phase, based on peak candidates extracted in the time domain, the unintentional interference movement of the hand is removed through short-time Fourier transform in the frequency domain to reduce the noise of pedestrian dead reckoning. During the observation phase, we introduce a magnetic interference coefficient to model and quantify the degree of electromagnetic interference in different environments, thereby improving the accuracy of indoor magnetic headings and enhancing the alignment of particle swarms with real-world directional constraints. Furthermore, based on passable semantic information, the indoor map is segmented into distinct probability regions, allowing the particle filter to adaptively adjust the weight of the particle swarm when moving between regions, thus improving the robustness of the overall fusion system by preventing particles from entering infeasible areas. Experiments and validations were carried out in a large shopping mall and parking lot with multiple devices. Results demonstrate that the proposed method improves the average positioning accuracy by approximately 25% compared to the Bluetooth-only positioning system, with a 15% increase in cumulative distribution probability within 3 m.

P-Permutation equivalences between blocks of group algebras

We extend the notion of a p-permutation equivalence between two p-blocks A and B of finite groups G and H, from the definition in [5] to a virtual p-permutation bimodule whose components have twisted diagonal vertices. It is shown that various invariants of A and B are preserved, including defect groups, fusion systems, and Külshammer-Puig classes. Moreover it is shown that p-permutation equivalences have additional surprising properties. They have only one constituent with maximal vertex and the set of p-permutation equivalences between A and B is finite (possibly empty). The paper uses new methods: a consequent use of module structures on subgroups of G×H arising from Brauer constructions which in general are not direct product subgroups, the necessary adaptation of the notion of tensor products between bimodules, and a general formula (stated in these new terms) for the Brauer construction of a tensor product of p-permutation bimodules.

FusionOC: Research on optimal control method for infrared and visible light image fusion

Infrared and visible light image fusion can solve the limitations of single-type visual sensors and can boost the target detection performance. However, since the traditional fusion strategy lacks the controllability and feedback mechanism, the fusion model cannot precisely perceive the relationship between the requirements of the fusion task, the fused image quality, and the source image features. To this end, this paper establishes a fusion model based on the optimal controlled object and control mode called FusionOC. This method establishes two types of mathematical models of the controlled objects by verifying the factors and conflicts affecting the quality of the fused image. It combines the image fusion model with the quality evaluation function to determine the two control factors separately. At the same time, two proportional-integral-derivative (PID) control and regulation modes based on the backpropagation (BP) neural network are designed according to the control factor characteristics. The fusion system can adaptively select the regulation mode to regulate the control factor according to the user requirements or the task to make the fusion system perceive the connection between the fusion task and the result. Besides, the fusion model employs the feedback mechanism of the control system to perceive the feature difference between the fusion result and the source image, realize the guidance of the source image feature to the entire fusion process, and improve the fusion algorithm's generalization ability and intelligence level when handling different fusion tasks. Experimental results on multiple public datasets demonstrate the advantages of FusionOC over advanced methods. Meanwhile, the benefits of our fusion results in object detection tasks have been demonstrated.

Enhancing the Purification and Stability of Superoxide Dismutase by Fusion with Thermoresponsive Self‐Assembly of Elastin Like Polypeptide

AbstractElastin‐like polypeptide (ELP) is a thermo‐sensitive biosynthetic polymer composed of a Val‐Pro‐Gly‐Xaa‐Gly repeating unit possessing a sharp reversible phase transition property at specific temperatures. Here, ELP was fused to human superoxide dismutase 1 (hSOD1) modified with His tag to produce recombinant hSOD1‐Linker‐ELP‐His (hSODLEH) which was expressed in E. coli and purified via inverse thermal cycling (ITC) and Ni‐NTA resin. The results showed that ELP tag did not affect the soluble expression of SOD1. The purification by ITC was superior to Ni‐NTA resin due to its convenient purification process, improved recovery rate and purification fold, thus indicating industrial suitability for large scale protein purification in a cost‐ and time‐efficient manner. Moreover, one round of ITC was sufficient for the recovery of highly purified recombinant SOD. The results further showed that ELP improved the stability of the SOD, and did not affect its secondary structure nor its ability to bind divalent metal ions. Overall, ELP‐protein fusion system could be a promising tool for large scale enzyme purification.

Overview of the early campaign diagnostics for the SPARC tokamak (invited).

The SPARC tokamak is a high-field, Bt0 ∼12T, medium-sized, R0 = 1.85m, tokamak that is presently under construction in Devens, MA, led by Commonwealth Fusion Systems. It will be used to de-risk the high-field tokamak path to a fusion power plant and demonstrate the commercial viability of fusion energy. SPARC's first campaign plan is to achieve Qfus > 1 using an ICRF-heated, <10MW, high current, Ip ∼ 8.5 MA, L-mode fueled by D-T gas injection, and its second campaign will investigate H-mode operations in D-D. To facilitate plasma control and scientific learning, a targeted set of ∼50 plasma diagnostics are being designed and built for operation during these campaigns. While nearly all diagnostics are based on established techniques, the pace of deployment, relative to the first plasma, and the harshness of the thermal, electromagnetic, and radiation environment are unprecedented for medium-sized tokamaks. An overview of the SPARC diagnostic set is given, providing context to further details communicated by the SPARC team in companion publications that are system-specific. The system engineering philosophy for SPARC diagnostics is outlined, and the design and engineering verification process for components inside and outside the primary vacuum boundary are described. Diagnostics are mounted directly to the vacuum vessel as well as housed within a series of eight midplane and 24 off-midplane replaceable port plugs. With limited exceptions, signal conditioning, digitization electronics and cameras as well as lasers and microwave sources are localized to a series of five Diagnostic Lab spaces, totaling ∼350m2, located >15m from the center of the tokamak, on the other side of a 2.4m concrete shielding wall. A series of 31 large-scale penetrations have been included in the SPARC Tokamak Hall to facilitate integration of early campaign diagnostics and to provide upgradability.

Research on the fusion positioning system of UWB/LiDAR based on the algorithm of SPF and KF

In order to overcome the disadvantages of single sensor localization in complex indoor environments, this paper proposes a design scheme for the ultra-wide band (UWB) and LiDAR co-location fusion system. To attain the ideal positioning effect of this system, a segmented point fusion approach based on Euclid's theorem is put forward to optimize the conventional extended Kalman filter and unscented Kalman filter algorithms. It can effectively reduce the positioning error of UWB in non-line-of-sight environments and under the multipath effect, and also assist LiDAR in correcting trajectory drift in sparsely textured scenes. Through both simulations and experiments, the feasibility of the proposed algorithm in the UWB/LiDAR positioning system is verified. The results reveal that the positioning error of the enhanced multi-sensor fusion algorithm is reduced by 22% compared with the original algorithm and 25.7% compared with the single sensor positioning method.